db_output.c revision 18298 
1/*
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
11 *
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19 *  School of Computer Science
20 *  Carnegie Mellon University
21 *  Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 *
26 *	$Id: db_output.c,v 1.18 1996/05/08 04:28:35 gpalmer Exp $
27 */
28
29/*
30 * 	Author: David B. Golub, Carnegie Mellon University
31 *	Date:	7/90
32 */
33
34/*
35 * Printf and character output for debugger.
36 */
37
38#include <sys/param.h>
39#include <sys/systm.h>
40
41#include <machine/cons.h>
42#include <machine/stdarg.h>
43
44#include <ddb/ddb.h>
45#include <ddb/db_output.h>
46
47/*
48 *	Character output - tracks position in line.
49 *	To do this correctly, we should know how wide
50 *	the output device is - then we could zero
51 *	the line position when the output device wraps
52 *	around to the start of the next line.
53 *
54 *	Instead, we count the number of spaces printed
55 *	since the last printing character so that we
56 *	don't print trailing spaces.  This avoids most
57 *	of the wraparounds.
58 */
59static int	db_output_position = 0;		/* output column */
60static int	db_last_non_space = 0;		/* last non-space character */
61int	db_tab_stop_width = 8;		/* how wide are tab stops? */
62#define	NEXT_TAB(i) \
63	((((i) + db_tab_stop_width) / db_tab_stop_width) * db_tab_stop_width)
64int	db_max_width = 79;		/* output line width */
65
66static void db_putchar __P((int c, void *arg));
67
68/*
69 * Force pending whitespace.
70 */
71void
72db_force_whitespace()
73{
74	register int last_print, next_tab;
75
76	last_print = db_last_non_space;
77	while (last_print < db_output_position) {
78	    next_tab = NEXT_TAB(last_print);
79	    if (next_tab <= db_output_position) {
80		while (last_print < next_tab) { /* DON'T send a tab!!! */
81			cnputc(' ');
82			last_print++;
83		}
84	    }
85	    else {
86		cnputc(' ');
87		last_print++;
88	    }
89	}
90	db_last_non_space = db_output_position;
91}
92
93/*
94 * Output character.  Buffer whitespace.
95 */
96static void
97db_putchar(c, arg)
98	int	c;		/* character to output */
99	void *	arg;
100{
101	if (c > ' ' && c <= '~') {
102	    /*
103	     * Printing character.
104	     * If we have spaces to print, print them first.
105	     * Use tabs if possible.
106	     */
107	    db_force_whitespace();
108	    cnputc(c);
109	    db_output_position++;
110	    db_last_non_space = db_output_position;
111	}
112	else if (c == '\n') {
113	    /* Newline */
114	    cnputc(c);
115	    db_output_position = 0;
116	    db_last_non_space = 0;
117	    db_check_interrupt();
118	}
119	else if (c == '\r') {
120	    /* Return */
121	    cnputc(c);
122	    db_output_position = 0;
123	    db_last_non_space = 0;
124	    db_check_interrupt();
125	}
126	else if (c == '\t') {
127	    /* assume tabs every 8 positions */
128	    db_output_position = NEXT_TAB(db_output_position);
129	}
130	else if (c == ' ') {
131	    /* space */
132	    db_output_position++;
133	}
134	else if (c == '\007') {
135	    /* bell */
136	    cnputc(c);
137	}
138	/* other characters are assumed non-printing */
139}
140
141/*
142 * Return output position
143 */
144int
145db_print_position()
146{
147	return (db_output_position);
148}
149
150/*
151 * Printing
152 */
153void
154db_printf(const char *fmt, ...)
155{
156	va_list	listp;
157
158	va_start(listp, fmt);
159	kvprintf (fmt, db_putchar, NULL, db_radix, listp);
160	va_end(listp);
161}
162
163int db_indent;
164
165void
166db_iprintf(const char *fmt,...)
167{
168	register int i;
169	va_list listp;
170
171	for (i = db_indent; i >= 8; i -= 8)
172		db_printf("\t");
173	while (--i >= 0)
174		db_printf(" ");
175	va_start(listp, fmt);
176	kvprintf (fmt, db_putchar, NULL, db_radix, listp);
177	va_end(listp);
178}
179
180/*
181 * End line if too long.
182 */
183void
184db_end_line()
185{
186	if (db_output_position >= db_max_width)
187	    db_printf("\n");
188}
189